Laurell, F

Abstract [en]

n this work we measure how photodarkening affects the optical efficiency for three different Yb/Al -doped silica fibers operating at 980€‰nm , one of which is codoped with cerium. A volume Bragg grating is used for linewidth control added rejection of amplified spontaneous emission. Several hours of degradation-resistant operation is obtained with the Ce-codoped fiber, while for the Yb/Al doped fibers a large drop in efficiency is observed within the first hour of operation. Our results show that Yb/Ce/Al -doped fibers could be excellent candidates for high-power 980€‰nm fiber laser sources._x000D_